The use of transaction cards has increased tremendously over the past couple of years. These cards are used for a variety of purposes, including, credit cards, security-identification cards to control access to secured areas and devices, and bank cards for use in automatic teller machines.
Typically, the transaction card has information encoded on the card to identify the cardholder. This information may be magnetically, electronically or optically encoded. For example, a financial transaction card such as a credit or debit card has the necessary account information stored in a magnetic strip on the back of the card.
As the use of transaction cards has increased, it has become desirable to increase the functionality in the cards by encoding additional information on the card, by making it possible to change such information, and by providing processing and/or input/output capabilities. For example, Moreno, U.S. Pat. No. 3,971,916 describes the use of a semiconductor memory for the storage of information. Ugon, U.S. Pat. No. 4,211,919 describes the addition of a microprocessor to the card to control the input and output of information from the memory. Dreifus, U.S. Pat. No. 4,575,621 also describes a microprocessor based system which can operate in conjunction with a terminal or operate in a stand-alone mode during which it monitors itself for abnormal conditions which may be caused by component failure or physical intrusion of the card.
These microprocessor based transaction cards are often referred to as "smart cards". However, these cards are still limited in that they are constructed to perform a predetermined function. Some smart cards prohibit any modification of the card once the card is fully assembled. The microprocessor in Ugon controls the input and output of information from memory. In Dreifus, a ROM stores system program information which cannot be changed. Instead the system information stored in ROM may be modified by information stored in RAM. However, the original programmed function of the card remains and is never permanently changed or removed from the card.
In addition, the above described cards are typically operated in conjunction with a terminal device rather than independently of any such device. Finally, these cards were not designed to be "user friendly". With prior art transaction cards, the cardholder has to memorize the proper procedure to operate the card.